43rd Guksu - Rui Naiwei's March to the Top

Happy New Year everyone! I hope 2010 was good to you and 2011 is better. I'm going to take a quick break from the Shusaku series to do a few games from the 1999 Korean Guksu challenger final and title match. This tournament was the first time a female pro won a title match open to both sexes. Rui Naiwei is probably the strongest female Go player in the world and, as we are about to see, is among the strongest Go players regardless of gender. Here we see her play Lee Changho, considered to be the world #1 Go player by many, in the final to determine the challenger to the Guksu title. Because it is the longest running title in Korea the Guksu title is very prestigious and is considered to be akin to a national championship title.

Our first game is the final of the preliminary tournament to determine the challenger to the title holder Cho Hunhyun. Rui Naiwei takes black against Lee Changho who is given a komi of 6.5. This is a fierce fighting game so my commentary will only focus on some of the key aspects of the overall battle.

Fig. 1

1-16

Fuseki - Black maps out a framework with the small Chinese opening in the lower side. Black 7 is in the modern style, establishing a large framework instead of reinforcing locally. Black 7 is possible because of the aji of jumping into the corner at C3 and sacrificing black 5. Alternatively, black can also jump to F5 if the lower right framework becomes more important. After the approach at 8 black could play at 12 directly to establish a large framework but 9 strikes a good balance between the corner and the right side. White establishes a high base with 10 and 12 and black approaches at 13 in the upper left. White pincers and after black's far reaching jump to 15 white intercepts at 16 starting a fight. This closes the fuseki of the game. Black has sketched out a powerful framework on the lower side and has engaged white in the upper left on slightly unfavorable ground. White has a useful formation in the two space extension on the right that is full of flexibility and a general advantage on the left side.

Fig. 2

17-39

A Complicated Joseki - Black sacrifices the stone at G16 to play out a fighting joseki and sieze the corner. Through 39 black gets the corner and some territory on the left but there is a lot of bad aji with the two stones at 17 and 23. These stones must escape, which they can, to get enough liberties to ensure the capture of the five white stones on the inside. White has many ways of exploiting this aji including the option of playing a ladder block around O5 although this would be somewhat crude, particularly if played immediately. White is also able to take sente so the result is fair. The focus turns to the upper right. White will look to take advantage of the aji left in 17 and 23. This situation is a good opportunity to practice your ladder reading. Not only is there the obvious ladder heading towards towards the lower right but make sure you can see what happens if white plays at G12 to give you one idea of how narrowly 17 and 23 can currently escape.

Fig. 3

 40-58

ChangHo Attacks - The 3-3 invasion is uncommonly severe because of the presence of the strong white formation, sitting on the fourth line and exuding power, on the right. This invasion now steals the base of the two black stones in the corner and force them to seek safety in the center. Black deviates from joseki with 53 which is commonly at O13 but 53 in the game leaves no weaknesses behind. After white jumps to 54 black turns to the left side to resolve the situation by escaping decisively with 55 and 57. The timing of these moves is perfect. Inevitably the coming fight will spill across the ladders that white can use to capture the two black stones and if those two black stones are captured the whole black corner collapses. Rui makes the correct reinforcement allowing white to close off the top with 58 and laying the groundwork for the difficult fight to come. It is important, if you like to attack, to keep your own positions secure before launching an all out assault. If white's stones were weak and black's were strong the descent to P19, separating the white corner from the outside stones, would be key to keeping white's outside stones isolated. As it is, however, these stones are backed up by the thick white formation in the the upper left and black is more focused on escaping into the center than attacking.

Fig. 4

59-82

Rui Hangs Tough - Rui moves out smartly with 59 and 61, defends the lower side with 63 and hanes at the head of two stones with 65. The common sense move would be to connect at 68 and run into the center but Rui has a better plan. She wedges at 67 and ignores white's atari at 68 to thrust at 69. If white could capture 65 by playing at L10 and making a ponnuki he would generally be satisfied but Rui gives no quarter and white doesn't have the time to capture since he has to save his stone on the right starting with 70. Continuing to 82 he makes eye shape on the right. The downside is obvious as black slices through white's position and even gets to block at 81 while white barely manages to get a single eye through 82. I feel that white has slipped somewhere here. Perhaps giving way and simply playing 68 at 69 would have been better. It is true that the large black dragon has now been cut off but it has many liberties and the key white cutting stones at 60 and 64 are now in a precarious position. White has been too busy saving the stones on the right side to capture at L10 and now when black extends out of atari by setting 65 into motion white's stones look nearly dead already.

Fig. 5

 83-124

Rui Takes Control - When black extends at 83 the position seems to have turned decisively against white. With 86 and 88 white seals black in and makes life on the right but Rui pushes at 89 and 91 before jumping ahead to 93. White sacrifices a stone to increase liberties by playing 96 in sente before counterattacking with the push and cut of 98 and 100. Through 24 the fight gets out of hand with the seven black stones from 19-91 in the center trapped in a capturing race with the white stones in the center/lower right. Right now the white group has four liberties and after 24 the black group has 3 so from here on out it will be a battle to hold black to four liberties.

Fig. 6

125-147

To No Avail - Black turns at 25 and while white tries valiantly to hold the black group to four liberties through to 46 there are too many weaknesses in the white formation and with the black atari at 47 the white possition crumbles. The reason white resigned here is because black can start a ko by playing L18, white K17, black M19, white N18 followed by another atari at J17. Once white escapes to K18 black plays at K19 to start a ko. This ko is impossible for white because black can use moves against the white group in the capturing race as ko threats. If white tries to fill a liberty as a ko threat black will just take the ko, capturing 4 white stones by playing at J18 and gaining enough liberties to win the capturing race. If white ignores a black threat against the lower right group and takes the ko then black will be one liberty ahead in the capturing race and win that way. The conclusion is that white cannot win both the ko and the capturing race where he needs to win both to stay in the game so white resigns. 

This is the first game in our 43rd Guksu review of Rui Naiwei's victory over the top of the Korean Baduk pro ranks. In less than a 150 moves this game was decided. Perhaps you have some newfound respect for Rui Naiwei now if you were unfamiliar with her before, my own country owes her a great debt as she has been instrumental in spreading the game around the United States. Next time we'll look at the championship match between the challenger Rui and the title holder Cho Hunhyun.